WASHINGTON (AP) _ Democrats and human rights advocates criticized President Bush's veto Saturday of a bill that would have banned the CIA from using simulated drowning and other coercive interrogation methods to gain information from suspected terrorists. Bush said such tactics have helped foil terrorist plots. His critics likened some methods to torture and said they sullied America's reputation around the world. "This president had the chance to end the torture debate for good, yet he chose instead to leave the door open to use torture in the future," said Democratic Sen. Dianne Feinstein of California, a member of the Senate Intelligence Committee. She said Bush ignored the advice of 43 retired generals and admirals and 18 national security experts, including former secretaries of state and national security advisers, who supported the bill. "Torture is a black mark against the United States," she said. The bill would have limited the CIA to 19 interrogation techniques that are used by the military and spelled out in the Army Field Manual. Bush said he vetoed the measure because it is important for the CIA to have a separate and classified interrogation program for suspected terrorists who possess critical information about possible plots against the United States. Bush, who used his weekly radio address to announce the veto, said the program had helped stop plots against a Marine camp in Djibouti and the U.S. consulate in Karachi, Pakistan, and plans to fly passenger planes into a Los Angeles tower or London's Heathrow Airport and city buildings. "Were it not for this program, our intelligence community believes that al-Qaida and its allies would have succeeded in launching another attack against the American homeland," the president said. House Speaker Nancy Pelosi said the nation's ability to lead the world depends on its morality, not military might. "We will begin to reassert that moral authority by attempting to override the president's veto next week," said Pelosi, D-Calif. Based on the margin of passage in each chamber, it may prove difficult for the Democratic-controlled Congress to turn back Bush's veto. It takes a two-thirds majority, and the vote was 222-199 in the House and 51-45 in the Senate. Bush said he did not oppose specifically over waterboarding, a technique that simulates drowning. The Army banned the use of waterboarding or sensory deprivation on uncooperative prisoners in 2006. The CIA, which also prohibited the practice in 2006, has acknowledged using waterboarding on three suspected terrorists in 2003. Bush said waterboarding currently is not part of the CIA program. The attorney general has deemed that program legal under domestic and international law, he said. Still, waterboarding remains in the CIA's tool kit. The technique can be used, but it requires the consent of the attorney general and president on a case-by-case basis. Bush wants to keep that option open. "I cannot sign into law a bill that would prevent me, and future presidents, from authorizing the CIA to conduct a separate, lawful intelligence program, and from taking all lawful actions necessary to protect Americans from attack," Bush said in a statement. Democrats say the CIA should be restricted to the techniques in the Army Field Manual. They include the "good cop-bad cop" routine; making prisoners think they are in another country's custody; and separating a prisoner from others for up to 30 days. In addition to waterboarding, the field manual prohibits hooding prisoners or putting duct tape across their eyes; stripping prisoners naked; and forcing prisoners to perform or mimic sexual acts. It also prohibits beating, burning or physically hurting prisoners in other ways; subjecting them to hypothermia or mock executions. It does not allow food, water and medical treatment to be withheld. Dogs may not be used in any aspect of interrogation. Waterboarding involves strapping a person down and pouring water over his cloth-covered face to create the sensation of drowning. It has been traced back hundreds of years to the Spanish Inquisition and is condemned by nations around the world and human rights organizations as torture. In a memo to CIA employees Saturday, CIA Director Michael Hayden said the Army Field Manual does not "exhaust the universe" of lawful interrogation techniques. "There are methods in the CIA's program that have been briefed to our oversight committees, are fully consistent with the Geneva Convention and current U.S. law and are most certainly not torture," Hayden wrote. Sen. Jay Rockefeller, chairman of the Senate Intelligence Committee, said he had heard nothing to suggest that the CIA, through enhanced interrogation methods, had obtained information to thwart a terrorist attack. "On the other hand, I do know that coercive interrogations can lead detainees to provide false information in order to make the interrogation stop," said Rockefeller, D-W.Va. There also are concerns that the use of waterboarding would undermine U.S. human rights efforts overseas and could place Americans at greater risk of being tortured if they are captured abroad. "The president's refusal to sign this crucial legislation into law will undermine counterterrorism efforts globally and delay efforts to rebuild U.S. credibility on human rights," said Elisa Massimino, Washington director for Human Rights First. Bush objected to two other provisions: -- A new independent inspector general for the government's intelligence agencies to improve coordination and information-sharing. Bush said the position was unnecessary. -- Senate confirmation of the directors of the National Security Agency and National Reconnaissance Office. Bush said that could delay the directors' ability to take over quickly and risk injecting politics into the selection process.